Telephone system



A. RAYNSFORD.

TELEPHONE SYSTEM.

APPLICATION FILED Nov. 25, I919.

Patented D0513, 1921.

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Application filed November 25, 1919. Serial No. 3405484.

To aZZ'whom it may concern: v

Be it known that I, ARTHUR RAYNSFORD, a citizen of the United States, residing-at New York, in the county of New York, State of New York, have invented certain new and useful Improvements in Telephone Systems, of which the following is. afull', clear, concise and exact description.

This invention relates to telephone systems and more 1 particularly to improved signaling arrangementsfor such systems.

It is the object of this invention to provide in a link circuit with which connections may be established through different types'of cord circuits, means responsive tothe disestablishment of a connection at the answering end of the'link circuit foroperating a signaling device associated with the particular cord circuit employed in establishing the connection.

In the present embodiment of this invention there isprovided a link circuit terminating at one end in multiple jacks at an operators position and at the other end in the springs of an operators listening key. Two types of cord circuits are provided for use in establishing connections with this link circuit. One of these cord circuits is of the type which may be used for connecting with central energy trunk lines provided with a polarized supervisory relay which controls. a disconnect signal. The

other cord circuit is of the type which may be employed in connection with magneto or toll trunk lines and is provided with an alternating current supervisory relay to control a disconnect signal. The insertion of the plug of either of these cord circuits in the jack of the link circuit controls relays associated with the link circuit to selectthe type, of current which will operate the "supervisory relay in the cord circuit being used, so that when the connection is discstablished the selected current is impressed upon the link and cord circuits to operate the supervisory relay of the cord circuit to give a disconnect signal.

In the drawing are shown two plugs which may be those at one end of the respective cord circuits described, or may be at opposite ends of a single cord circuit which with either. magneto or A link circuit is from multiple jacks to an may be employed shown leading 'operators listening key. r 7

and is lrelease relay 211 from through the winding of i It is believed that: the invention willbe readily; understood from aconsi'deration off I call from a central energy station. 32 with that end of the cord circuit 1 which is not shown in the drawing, desiring to extend the connection to a supervisory operator, inserts plug 2 in jack 3, of thezli-nk'ciiuit leadlng to the supervisory .operators posh tion and operates her ringing'key to;- close the alternate contacts of key springs t and e. Upon the insertion of the plug'-m the ack a circuit .is'v completed from grounded battery through the winding of sleevefrelay 6, sleeve'contactsof'plug .2 and" jack 3, through the-windings 0t relay 7 and: mar.- glnal relay 8 to ground. Relay 6 has a low resistance winding and" permits, sufficient current to flow over the circuit traced to energize relays 6 and: 7 and marginal relay contacts of plug 2 and jack. 3, ring i conductor 9, conductor 10, right-hand armature andiback contact of relay'll, conductor "12,

through the ringer at the superlvisory operators position, condenser 13, tip conductor 14:, tip contacts of jack :3 .and' plug 2, and alternate contacts of spring 4: j to ground.

-.The supervisory operatonhearing the bell which is rung in the circuit traced,":depresses her listening key15, including" her tel'ephone in the' line circuit,-and completing a circuit from ground, contact: 16,

through the winding of relay 17 to grounded battery, to operate relay 17. Relay 17 in attracting its left-hand armatures .disconnects the battery which was con'nected to conductors l4: and 9..through impedance coil 18 by the operation of relay 8,1and in attracting its "outer 'right han'd armature completes a circuit from groundedibattery,.-

outer right-handarmature andv front'contact of relay 17, through the winding of 1 relay 19 and normal c'ontactof holding key 20 to ground. Relay 19 is operated in this circuit and locked up through its front. contact and'left-hand armature togrounded battery at the armatureof relay 7. In at. tracting, its right-hand armature relayv 19 completes an energizing: circuit for slow grounded battery relay 21, right-hand .110"

armature and front contact of relay 19, front contact and inner right-hand armature of relay 17to' ground. Relay 21 in operating completes an energizing circuit for relay 1} In attracting its right-handarmature relay 11 interrupts the ringing circuit, and the supervisory operator may now converse with the calling party at station 32, talking current being supplied from a battery 33 associated with the calling line of which the free pole is connected through a winding of impedancecoil 34 to the ring side of the line, and the grounded pole through another winding to the tip side of the line. Current of this polarity flowing through the line will not operate polarized relay 22 associated with the cord circuit.

At the conclusion of the conversation the supervisory operator in releasing key 15 opens contact 16,thereby interrupting the circuit for relay 17, which deenergizes to complete a circuit from grounded battery through the left-hand winding of impedance coil-'18, front contact and inner armature of marginal relay 8, back contact and outer left-hand armature of relay 17, conductor '14, tip contacts-of jack 3 and plug 2, normal contact of spring 4, through the winding of relay "22, normal contact of spring 5, ring contacts of plug 2 and jack 3, conductor 9, inner left-hand armature and back contact of relay 17 outer armature and front contact of relay 8, through the right hand winding of impedance'coil 18 to ground. The current flowing in this circuit is of the proper polarity to energize the cord circuit polarized supervisory relay 22, which attracts its armature to complete a circuit from grounded battery, fronthcontact and armature of re- .lay 6, lamp 23, frontcontact and armature ofrelay 22 to ground. Lamp 23 is lighted in this circuit to indicate tothe operator thatshe'may remove plug 2 from jack In removing plug 2 from jack 3tl1e circuits of relays 6, 7, 8 and 22 are interrupted and these relays retract their armatures. Relay 6 opens the circuit of lamp 23 which is extinguished; Relay 7 opens the locking circuit of relay '19 which thereupon retracts its armatures and the system is completely restored If an operator has answered a call from a magneto station with'one end of a cord circuit 24 andvdesires to extend the connection to-a supervisory operator, she inserts plug 25v in jack 3 and depresses the ringing key associatedwith cord 24 to close the alter 'nate contacts ofsprings 26 and 27. The in sertion of the plug in the jack completes a circuit from grounded battery through the Winding of sleeve relay 28, sleeve contacts of plug 25 and jack'3, windings of,- relay 7 and marginal relay 8 to ground. Relay 28 has a resistance sufliciently high to prevent r the energization of marginal relay 8 in this i circuit, but relays 28 and 7 are energized.

from a source ofalternating current, through the alternate contact of spring 27, ring contacts or plug 25 and-jack 3, conductor 10, right-hand armature and .backcontact of relay 11 conductor 12, through the supervisoryoperators call bell and condenser-13, conductor 14, tip contacts of jack 3 and plug 25, and alternate contact of spring 26 to ground. The supervisory operator responds by depressing her key 15 to includeher telephone set in the line circuit and close contact 16. Relay 17 is energized and completes the previously traced circuit for relay 19, which looks up over the circuit previously traced and energizes slow release relay 21 in the manner already described. Relay 21 completes a circuit for relay 11 which there a upon attracts its armatures. In attracting its right-hand armature relay 11 interrupts the ringing circuit, and in attracting its left-hand armatures connects ground and a source of alternating current to the back contacts of the left-hand armatures of relay 17, so that when this; relay is subsequently deenergized, alternating current will flow over the line. V Should the supervisory-operator desire to hold the connection whileanswering another call, she might operate her holding key20. The operation of key 20 providesa substi tute circuit for relay 17 to prevent the source of alternating current from being connected to the line, but interrupts the holding circuit of relay 19 which is deenergized to open the circuit of relay 21; Relay 21 in retracting its armature opens the circuit of relay 11, which is deenerglzed. Then the operator desires to continue the conversation, she

again depresses her listening keyand re-.

leases her holding key. The closure of the normal contact of key 20 again completes the circuit for relay 19 which operates relays 21 and 11 as before.

Atthe conclusion of the conversation the operator releases her 7 listening key 15, disconnecting her'telephone set from the link circuitand opening contact 16. Relay 17 isdeenergized to completethe circuit from the'source of alternating current, front contact and inner left-hand armature of relay 11, back contact and outer armature of relay 8, back contact and inner left-hand armature of relay 17 conductor 9,

ring contacts of jack 3 andplug 25, normal 1 contact of spring 27 through the left-hand winding of relay 30, condenser 31, normal contact of spring 26, tip contacts of plug 25 andjack 3, conductor 14, outer -left-hand cuit for lamp 29, so

armature and back contact of relay 17, inner armature and back contact of relay 8, outer left-hand armature and front contact of relay 11 to ground. At the same time that this circuit was completed relay 17, in retracting its inner ri ht-hand armature, interrupted the circuit for relay 21. Relay 21 being slow to release maintains the circuit for relay 11a sufficient length of time to allow supervisory relay 30 to be operated in the circuit for alternating current just traced. Relay 30 in attracting its armature completes a locking circuit for itself and a cirthat lamp 29 is lighted and remains so until the operator removes plug 25 from jack 3. In removing the plug from the jack the circuit for relays 28 and 7 is opened. Relay 28 in retracting its armature opens the circuit for lamp 29 which is extinguished and the locking circuit for relay 30, which relay is thereupon deenergized. Relay 7 in denergizing opens the locking circuit for relay 19 which becomes inert and the system is now completely restored.

Thus by the use of sleeve relays of ditferent resistance in association with cord circuits having supervisory relays responsive to difierent varieties of current, the proper variety of current to operate the supervisory relay of each cord circuit will be automati- -ally selected upon the insertion of the plug into the calling jack of a link circuit, and upon the subsequent interruption of the link circuit the selected source of current will be connected over said link circuit to the cord circuit supervisory relay for a sufiicient time to operate this relay to give a disconnect signal.

What is claimed is: i

1. In a telephone system the combination with a link circuit of a plurality of dififerent types of cord circuits for connection therewith, a signaling device and a relay responsive to a particular variety of current for operating said signaling device associated with each cord circuit, a telephone set, means for connecting said telephone set to said link circuit, a plurality of sources of current, and means operated in response to the disconnection of said telephone set from said link circuit to connect one of said sources of current to said link circuit to operate the signaling device of the. connected cord circuit.

rent, and means responsive to the disconnection of said telephone set from said link circuit for connecting the selected source of current to said link circuit to operate the relay of the connected cord circuit.

3. In a telephone system the combination with a link circuit, of'a plurality of different types of cord circuits for connection therewith, a signaling device and an operating relay therefor responsive to a particular variety of current for each of said cord circuits, an extension for said link circuit,

means for connecting said link circuit to said extension, a plurality of sources of cur- 7 rent, means responsive to the connection of any one of said cord circuits to said link circuit for-selecting one of said sources'of' current, and means responsive to the disconnection of said extension from said link circuit for connecting the selected source of current'to said link circuit to'operate the relay of the connected cord circuit. v

4:. In a telephone system the combination with a plurality of sources of current, of a plurality oi cord circuits of different types, a disconnect signal and an operatingrelay therefor 'IBSPOIISlVG to a particular variety of current from said plurality of sources for each of certain of said cord circuits, a dis 7 connect signal and an operating relay therefor responsive to a different'varietyofcurrent from said plurality of sourcesfor each of others of said cord circuits, a link circuit, a relay associated with said link circuit selectively responsive to the connection to said link circuit of each type of cord circuit to select and connect the proper source of current to actuate the operating relay of the connected cord circuit. I

In witness whereof, I hereunto subscribe. my name this 21st day of November, A. D.,"

ARTHUR RAYNSFORD. 

